ANALYSIS AND QUANTITATIVE SIMULATION OF STOMATAL CONDUCTANCE OF ANEUROLEPIDIUM CHINENSE

Detailed measurements of leaf stomatal conductance and photosynthesis of Aneurolepidium chinense were used to analyze the relationship between stomatal conductance and environmental factors and to develop a leaf stomatal conductance model for A. chinense . The results show that leaf stomatal conductance of A. chinense is sensitive to photosynthetically active radiation ( PAR) , vapor pressure deficit ( VPD ) and air temperature ( Ta ). Stomatal conductance increased with increasing PAR and Ta and decreased with increasing VPD . Validations of Jarvis' and Ball's models based on field data of leaf stomatal conductance in A. chinense indicate that model is a better estimate of g s than Ball's. The relationship between leaf stomatal conductance( g s) and environmental factors could be expressed as:g s = PAR (-2.01Ta 2+147.74Ta-2321.11)/((444.62+PAR)(-538.04+VPD))This model will be very helpful to simulate the dynamic photosynthesis at both leaf and canopy scales and also to simulate the NPP of ecosystems and energy and water balances in the Soil Plant Atmosphere Continum (SPAC) .